Amit Kapila <amit.kap...@huawei.com> writes: >> AFAIR you can create pg_control from scratch already with pg_resetxlog. >> The hard part is coming up with values for the counters, such as the >> next WAL location. Some of them such as next OID are pretty harmless >> if you don't guess right, but I'm worried that wrong next WAL could >> make things worse not better.
> I believe if WAL files are proper as mentioned in Alvaro's mail, the > purposed logic should generate correct values. I've got a problem with the assumption that, when pg_control is trash, megabytes or gigabytes of WAL can still be relied on completely. I'm almost inclined to suggest that we not get next-LSN from WAL, but by scanning all the pages in the main data store and computing the max observed LSN. This is clearly not very attractive from a performance standpoint, but it would avoid the obvious failure mode where you lost some recent WAL segments along with pg_control. regards, tom lane -- Sent via pgsql-hackers mailing list (email@example.com) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers